Railway traffic controlling apparatus



June 13, 1944. 1 M PELlKAN n `RAILWAY TRAFFIC CONTROLLING APPARATUS 2 sheets-sheet 1 v Filed Aug. 5, 1942 .NN Ivm NN n N b M, NLT?! mgm@ A@ BSN,

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June 13, 1944. 1. M. PELIKAN RAILWAY TRAFFIC CONTROLLING APPARATUS Filved Aug. 5k, 1942 2 SheetSfSheeb 2 Patented June 13, 1944 n K,

UNITEDl STATES PATENT oFFicEj a l 2,351,540 f RAILWAY TRAFFIC coNrRoLLING John Pelikan,v Chicago, Ill., assignor to "The Union Switch and Signalv Company, Swissvale',`

Pa., acorporation of Pennsylvania i Apeueationliugusts,1942,'seria1No. 453,663I

I '1c claims. (craie-39)* v.

My inventionl relates to railway tralllc control. y V app'roach'lighting` the signals ling apparatus, andit has particular reference to the signaled stretch. s the organization of such apparatus into travlc An additional objectof my inventiQriS th?, controlling systems of thev type-inwhich code provision of a novel. and improved*railwaytraic' impulses of energy transmitted over either or Il controlling system'incorporating apparatu both line and track circuits are utilizedfor eff ranged to utilize a minimum of'power`.

fecting a control 0r controls. y .f: l Anotherobject of my invention isthecrganz In systems utilizing code impulsesr of energy, tion of railway traffic controlling apparatus energy supplied to a pair of conductors of a cona novel and improved formj of' railway' 'sv trol circuit is caused to vbe periodically inter- ,1,0 system.

rupted or coded in one or anotherof aplurality Y The above-mentionedand other,important` b; of distinctive manners each comprised of different jects and characteristic features which vvilljbe-IY patterns of alternate on and olf periods durcome readily apparent from thejiolloyvingdj ing which current does and does not flow, rescriptiomare attained in accordance with jthe jini spectively. This coded current is detected, trans- .1.5 vention byproviding'each of V a,plurality Otseglated and utilized for establishing control of tions Vof track with track circuit apparatusar'-, traiiic governing signals, and generally such enranged lon thel self-generating code principle' of ergy is constantly appliedto a circuit even though my copending application, Serial QN'ouAlSfiZflQ it is necessary to control a signal only when a The apparatusof these sections isarranged tozbe train is approaching thereto. Therevis, theref- (.20 normally deenergizedandeach section has'las'TsoQ-I fore, no particularly useful function for the curciatedtherewith means eflective to: supplyjenefrgy rent that is supplied -to the controlicircuit durwhen a train approaches its associated' section', ing the interval that a train does not approach .These meansinclude a stick relaywhichhas an the signal. In certain applications, particularly approachcontrolled pick-up. circuit made e'iecT where there is a limited supply of power as in 2li .tive when a train approaches, andzafstickcirvterritories Where primary batteries are the only `cuit that is effective .when ythe lsectic'gn is'occuped available sources, it is deemed desirablertoconf tomaintain the energy. availableinthe section. serve the power as much as possible by using it After the section becomes vacantthe avail` ble only when absolutely needed. My inventionr has enrgy. fllnCtOns to deenelgize, the 'stick @Y for an object the provision of a`V novel and im- 30 land restorerthe trackA circuit, apparatus tc* its proved railway signall systemincorporating nor'- normal condition.

mally deenergized control circuits ofuthe coded I shall describe oneiorm of apparatusjembody current class. More particularly.,an.object of my ling my invention, and shall thenpoint. vou t,the invention is the provision yof a novel and imnovel features thereof in claims.v proved form of railway traffic controlling'systems 35 Figs. lA-and 1B taken' together With `Fig-1A OX; incorporating normally deenergized track circuits v th/.left is a diagrammatic `Viewshowing appa-- which operate on the self-generatingv-code princiratus, embodying my imfention'.A y ple disclosed in my copending application, Serial In the drawings, apparatus embdyinsmyin- No. 443.240, filed on May'l, 1942', for Railway .vention is represented aD'pIi'edtO a, Strethof traflic controlling apparatus. 1 n u y o single -track railway ovehwhich traffic normally 4Another advantage of a signal system incorpooperates in the eastbound direction; igndicatedby rating coded track circuits'which operatejon the an arrow pointing from left to right as viewedin normally deenergized principle; isthat-'the life Atlle'.drawings. l The tlak Tails fand ,la,0f.the of the operating elements isextended by avoiding 'stretchv are divided by theusual insulated joints all unnecessary operations ofthe codeffollowing `4;; .2. into a plurality of. successive adjoining track and code transmitting apparatus. Anotherjobsections.. of. which 'four` sections are. shown, ject of my invention isjthe provisionofA a novel namely, sections D-E, Ef-F, 1-Ilj alidf and improved railway tranic controllingsystem' Each of these sectionsis` provided adjacent'it's incorporating coded track circuitsinwhichthe entranceV end.V with. `a traiiic,"controlli'ngrwayside life of the code operating and operated elements 5in-signal, designated by the reference. characters of the system is greatly increased. v Y with a suitably distinguishing prefix. .V'I'hese sig:

A further object of my invention.. l is `the pronals may be of any suitable type, butfor thepurvision of a novel and imprevedrailway traflc pose of the present. description it .will'betassumed controlling system incorporating normally, de- 4that-the signals. are vof the colorlighttype each energized track circuitsr and Vhaving.means rfor M .comprising .a plurality offlampsCr.- Y and;

which lamps when illuminated indicate clear, caution, and stop, respectively.

Certain of the track sections, namely sections F-H and H--J and other sections (not shown) extending to the right of section H--J, are provided with normally deenergized track circuit apparatus embodying my present invention, while the two other sections D-E and E-F are provided with normally energized track circuit apparatus which operates on the self-generating code principle disclosed in my copending application,y

Serial No. 443,240. The track circuit apparatus of these latter two sections are arranged to cotending from terminal B through back contact I4 of a relay OAP, hereinafter to be referred to, front contact I5 of relay IL, front contact I6 of relayIN and the filament of lamp G of signal IS to terminal C; when relay IN is released but relay IL is picked up, lamp Y of the signal is conditioned to become illuminated over an obvious circuitextending from terminal B through back contact I4 of relay OAP, front contact I5 of relay IL, back contact I6 of relay IN and the filament of lamp Y of signal IS to terminal C;

'and when both relays IN and IL are released,

operate with the apparatus'oflthe other sections c in such manner as to function als-'starting sections for the remaining sections of the'stretch', and the two sections D-E and. Ef-F will bere-A v ferred to hereinafter as monitor sections'f The track circuit arrangement of the first moni- Vreleasing relays, designated `by the reference charactersV IK, IL and IN,V respectively, and a polar stick relay IM. Relay IK is provided with a pick-up circuit which extends from one terminal B of 'a suitable source of current, such as va battery not shown but having its opposite terminals designated in the .drawing by the reference' characters B and C, through polarcontact 5 closed inthe reverse'or right-hand position,` as viewed in the drawing, ofthe polar armature'of relayITR, polar contact 6 closed in the normal or left-hand position of relay IM,y and the winding 'of relay` IK lamp R of signal IS is conditioned to become illuminated over a circuit extending from terminal VBjzthrough vbackjcontact I 4 of relay OAP, back 'contact I5 of'- relay IL and the filament of lamp R. of signal IS to terminal C. It is to be noted that the lamps of signal IS are normally dark and willbecome illuminated only when contact I4 is closed. This contact is operated by relay OAP associated-withfthe trackcircuitapparatus of the section extending to the left of section D-E, and lsuoli 'relay preferably is controlled by its associatedfapparatus in-a manner substantiallyccorresponding' to the manner hereinafter pointed out whereby relay ZAP' is' controlled by relay 2TR of section D-E. y

Relay -IM is a two-winding relay provided With l, anormal energizing circuit which extends from to terminalV C. Relay IK also is provided with anv auxiliary circuit in which fronty contact I 'of relay IL provides an alternate pathi around polar contact 6 of relay IM. Relay IL isprovided with an energizing-circuitv which may be vtracedirom vterminal B through polar contact 5 of relay ITR.

closed in its normal or left-hand position, frontv contact I0 of relay IK and the winding of relay IL to terminal C; Relay IN is connected through a filter device INF across a winding I I Vwhich has one portion or the other thereof supplied with unidirectional energy according as relay ITR is in its normal or its'reverse Vposition,.,respectively. Inthe normal position Aof thev relay, a circuit is completed from terminal Bthrough normal polar contact 5 vof relay ITR,front contact I0 of relay IK and the lower portion (as viewedin thedrawing) of winding II to terminal C; while in the reverse position of relay ITR an obvious circuit Vis completed from terminal .Brthrough 'reverse `polar contact 5 of relay` ITR and `the upper, por.-

Vtion of winding II to terminalCLjn condenser I2 connected across winding; II is proportioned" to tune the ,winding to effectiveresonan'ce at a` predetermined frequency hereinafter mentioned, and whenr the supply of vcurrent tov winding fII is Periodically reversed at'such frequency, relay, IN)

terminal B throughnormal polar contact AI8 of relay 'I'IR-, and one portion of the winding of relay I M to terminal C; with a reverse energizing circuitfwhich extends from terminal B through reverse polar contact I8 of relay I'I'R, front contact I9 of relay IK, and the other portion'of the winding ofrelayf'IM to terminal C; and with an auxiliary circuit which extends from terminal B through reverse 'polar contact I8 of relay ITR, backrcontact I9 lof relay IK, back contact 20 of relay` IL, and? the said one portion of the winding offrelay IM to terminal C.

" litelay 2TR is provided with a slow releasing impulse generating relay 2TPR which is normally energizedl over a circuit which may be traced from' terminalV Bthrough normal polar contact `2I"of relayvZIA'l.,` front contact V22 (which has the reference character 3L placed above the contact Ito indicate that it is controlled by relay 3L assotciatedwith thel adjoining advance section E-F), the winding of Jrelay ZTPR and to terminal C. Whenever'relay- 3L is released, thenv relay Z'IAPR becomes energized over anvobvious circuit includ- 'ing frontcontact 23 of an auxiliary slow pick-up relay 2HP,which relay is energized over a circuit including the source of current, normal polar contact 2I of relay'Z'I'R, back contact 22 of relay 3L andthewinding of relayZHP. 1'I'he arrangeslow releasing relay lZAP energized over an Vobvious circuit including reverse polar' contact 25'of relay Z'I'R. Relay ZAP is provided withv aV slow releasing repeater relay 2APP which is energized over an obvious circuit including front contact 26 of relay 2AP.

The trackcircuitl apparatus of the second monitor section, EF, is in general similar to thatfjust described for section D--liLv except that at times a shunt or short-circuit path is connected lacross the V-railscf sect-ion VE-F adjacent to endA E. This shunt circuit path is completed through back vcontact 28 of relay ZAP and front contact 29 cf relay ZAPP, 'and is effective after relay 2AP1releases Aand while relay ZAPP is still held up dueto its slowv release interval. The shunt circuit; path functions in a manner to be made .clear presently, to cause energy to be applied to the'remaining normally deenergized sections of the stretch.

The trackcircuit apparatus of the rst normally deenergized section F--H, is in general similar to the track circuit apparatus provided for section D-E. Howevensection F-H is provided with a stick relay'5SR and a stick repeater relay SSPR. Relay `SSR Ahas a pick-up circuit which 'extends vfrom terminal B through back contact 30 of relay4AP, and the Winding of relay SSR to terminal C; andv has a stick circuit which passes from terminal B through front contact 3| of relay 5L, front rcontact 32 and the winding of relay SSR to terminal C. An alternate stick circuit path for relay`5SR is completed when back contact 30 of relay AAP and front contact 32 of relay 5SH are closed, respectively.- Relay 5SPR has a pick-up circuit which Vmay be traced from terminal B `through back contact 3l of relay 5L, front contact 33 of lrelay 'ESR andthe winding of relay SSPRto terminalC. This relay also has a stick circuit in which front contact '34 of relay SSPR provides an' alternate path around front contact A33 of relay 5SR in the previously traced pick-up lcircuit of the relay.

Relays SSR and SSPR function to connect and disconnect relay STR from the rails of the associated section. When lboth relays SSR and ESPR are released, relay 'STR' and battery STB are placed on open circuit, with the result that no closed circuit track circuit can be completed for the section at this time, 'as will be made clear presently. Whenever relay SSR closes its front Contact 36 andor reiay'SSPR closes its front contact 31, then relay STR is connected in circuit with the track rails'elther alone or in series with battery TH, and hence the apparatus of section F-H is then'conditioned to .provide closed-circuit track circuits for the section;

The relays ESR and SSPR also function to control the supply of energy to the decoding relays 5K, 5L, 5M andK 5N of section F-H, in such a manner that when both relays SSR and SSPR are released, energy 'cannot be supplied to any of the named decoding relays,fbut Whenever relay ESR closes its front contact Eiland/or relay SSPR closes its fron-t contact 39, the apparatus is then conditioned to supply energy'to the decoding relays. f

The track circuit apparatus of section I-I-J, and also of the remaining sections (not shown) of the stretch, is substantially similar to the apparatus just described for section F-I-I, and

relays I'I'R'and` 2TH of sectionfDE are ener# example, energizes both relays [TR and 2TH. in series over a rst track circuit extending from one terminal of `battery ITB through normal polar contact 8 of relay IM, rail 'I, front contact 9 of relay ZTPR, the winding of relay 2TR, rail Ia and the Winding of relay ITR to the other terminalof battery ITB. This track circuit is completed when relay IM is in its normal position dueto the energization 0f the relay over its normal circuit including normal polar contact I8 of rrelay ITR, and when relay ZTPR/is energized to close its ffront contact 9. The polarity of current supplied from battery- ITB to the relays ITR and ZTR over the rst track circuit is 'such as to cause the relays to shift their'respective armatures from the illustrated position to the reverse or right-hand position, whereupon relay ZTPR becomes deenergized, and relay IM is caused to shift its polar armature to its reverse position, thereby opening or interrupting the 'first track circuit by disconnecting lbattery ITB from the track rails and relays I TR and 2TH. Relay 2TPR releases, at the end of its release period, and opens its front contact 9 to open the first track circuit at that point. Back contact 9 of relay 2'IPR now connects battery 2TB to relays ZTR and ITR in series over a second track circuit extending from one lterminal of battery ZTB through back contact 9 of relay ZTPR, rail I, reverse polar contact 8 of relay IM, the winding of relay ITR, rail la, the Winding of relay ZTR, and to the other terminal of battery ETB. The polarity `of current supplied from source 2TB 'to the relays over the second track circuit is the reverse of that supplied from battery ITB to the rst track circuit and causes the relays to shift their respective armatures back te their normal positions, whereupon relay 2'I'PR becomes energized and immediately picks up to open the second track 'circuit by vdisconnecting battery 2TB from the track rails and track relays, While relay IM becomes `energized over its normal circuit and shifts its polar contact member 8 to its normal position. The opening of reverse contact 8 opens the second track circuit and the closing of normal polar contact 8 closes the rst track circuit by Aconnecting battery ITB in circuit with both relays ITR and 2TH.. This cycle of operation continues as long as section D-E is vacant', hence relays ITR and 2TR are energized, in series, 'by energy derived alternately H fromv the two. sources TBJ-- Battery ITB, for

gized in series alternately first by current of one polarity derived from battery vITB and supplied over a rst track circuit and then by current of the opposite polarity derived from battery Z'IB and supplied over a second track circuit.' vEach one of these-sources is connected in circuit with the track rails and relays for relatively short intervals of time in-response to an impulse of energy received froml the other of such sources, with the result that each source of energy is caused to supply coded energy to the rails in response to code impulses of energy supplied `from the other of the sources to the rails.

The operation of track relaysl ITB. and ZTR in response to the self-generated code impulses is detected by means of the yassociated slow-acting relays IK, L and IN. Relay IK, for .example, rst becomes energized when reverse polar contact 5' of relay ITR and normal polar contact 6 of relay nIM are closed, and the relay picks up to close its front contact Iil toprepare a circuit for relay IL, which circuit becomes completedwhen vnormal polar Contact 5A of relay ITR closes. When relayv IL, picksuln, Ianothery circuit for relay IKis prepared, including reverse polar contact 5 of relay ITR and front contact. 'I of relay IL, hence when relay ITR operates its polar armature alternately to first oneV and then the other position relays IK and' IL arealternately energized. In addition with' relay IK picked up, polar relay IM is reversibly energized due to the operation of contact I8 of relay ITR. The operation of relay ITR Yalternately to its normal and reverse positions causes the direction of unidirectional Vcurrent'supplied to winding II to be periodically interrupted at a predetermined frequency that is determined largely by the slow release time ofv relay ZTPR. Condenser I2 and filter unit INFV are proportioned and adjusted in such manner that relayA IN ris at this time effectively energized andpicked up.v Relays IK, IL and IN are provided with slow 'releasing periods, attained in part at least by means of resistors I1 connected across their terminals, selected to maintain the relays in' their picked-up positions for intervals which bridge the intervals that the respective energizing circuits are open due to the operation of the polar contacts of relays ITR and IM. With these relays picked up, signal IS is conditioned to display its clear aspect and will do so when back contact I4 of relay OAP closes. At this time, relays'ZAPand `2APP are picked up since contact 25 of'relay 2TR alternately closes and opens to intermittently energize relay 2AP, which relay picks up in turn to energize and pick up relay 2APP.

The track circuit apparatus of section E-F operates in a manner generally similar to that described for Vsection D-E, with the difference that relay 5L of the section in advance (section F-H) is released, hence afterrelay 4TR operates to its normal position, relay 4TPR will-pick up only after relay 4HP picks up at the end of its slow pick-up interval. The slow pick-up period of relay 4HP is thus introduced into and added to the interval between successive impulses of energy from battery 4TB, hence these impulses occur at a frequency substantially lower than the frequency at which impulses are supplied from battery 2TB when relay 3L is picked up. This lower frequency of impulse supply causes operation of relay 3TR at a corresponding frequency and causes relays 3K and 3L to be picked up. Relay 3N is, however, released since at this lower frequency of operation of relay STR, winding II and condenser` I2 donot approach a resonant condition and the energysupplied therefrom to relay 3N is insufficient to pick up that relay. Signal 3S accordingly is conditioned to display its caution aspect and will do so when back contactI4 of relay 2AP closes.

At this time both relays 5TR` and` 'ITR are placed on open circuit since the 'associated stick and stick repeaterrelay's SR-'and SPR'are released. Relays 5K, 5L and 5N associated with relay STR and relays 1K, 'IL and IN associated with relay 1TR aretherefore, released, with the result that signals 5S and IS are conditioned to display their respective stop aspects but at this time are dark. When a trainV operatingon the stretch approaches section relay OAP associated with the section to the-left of section D-E will close its back contact I4, whereupon` lamp G of signal IS becomes. illuminated and is caused to display'its green aspect. This condition of the apparatus Vobtains until the vtrain enters section D- E, whereupon `atrain shunt isestablished in the section and relay 2TH. either'remainsinor assumes its normal position, while relay ITR either remains in or assumes its reverse position. In other words, with a train-in the section, the two track relays are caused to operate their polar armatures to positions out of correspondence. For example, when a train enters the section when battery ITB is connected tothe track rails, the train shunt established in the section prevents relay 2TR at the opposite section end from responding to such energy, hence relay 2TR remains in its normal position and relay ZTPR is maintained energized. Relay ITR, on the other hand, becomes energized in series with the train shunt and operates its polar armature to its reverse position, thereby reversing the energization of relay IM, which relay operates its polar armature in turn to disconnect battery ITB from the track rails. Relay ITR remains in its reverse position since no energy impulse of the opposite polarity is at this time impressed on the track rails, and relay IL flrst releases to open its front contact 'I whereupon relay IK also releases. Relay I M, however, now becomes energized by current of normal polarity over its auxiliary circuit including reverse polar contact I8 of relay ITR, back contact I9 of relay IK and back contact 20 of relay IL, whereupon normal polar. contacts 6 and 8 of relay IM close. 'Relay ITR now becomes energized again in series with the train shunt, by current of the polarity corresponding to the reverse position'of the relay, but no operation of relay I'I'R is ee'cted at this time since the relay already is in its reverse position. Relay IK, however, picks up over its pick-up circuit including reverse contact 5 of relay ITR and normal polar contact 6 of relay IM, and back contact I9 of relay IK opens to interrupt the previously traced auxiliary circuit for relay IM. Front contact I9 of relay4 IK is now'closed to complete the reverse circuit of relay IM, whereupon the polar contacts of that relay 'reverse to disconnect battery I TB from the track rails, and to deenergize relay IK. When that relay drops, relay IM again becomes energized by current of normal polarity and shifts its polar contact members 6 and 8.. 'I'his operation of relays IM and IK continues as long as the train shunt is maintained in the section, and has a function which will be pointed out hereinafter.

With relay ZTR held constantly in its normal position by the shunt established by the train in the section, relay 2AP releases to close its back contact I4 to apply energy to the lamps of signal 3S, and to open its front contact 26 and thereby deenergize relay 2APP.` Relay 2APP is held up, however, due to the slow releasing characteristics and at this time the previously, traced shunt circuit path is applied across the rails-of' section E-F. This circuit includes back contact 28 of relay 2AP and front contact 29 of relay 2APP, and it functions much in the same manner as if a train shunt were established across the track rails. is shunted away from relay- 4TR so that relay 4TR either remains in or assumes its normal position, while relay 3TR either remains in or assumes its reverse position. Relays 3M vand 3K are now caused to interact and operate to l,cause relay 3M to intermittently apply impulses ofenergy to the track rails. These impulses are at this time shunted away from track relayV 4TR by the "shunt circuit path, hence no operation-'of relayv4TR will be effected and as a resultrelayIAPis caused to release sinceits energizing circuit islield 'open when relay 4TR is in its normalpositiom'and back contact 30 of relay IAP closes lto'energizeV That is to say, energy from battery '3TB asma@ relay SSR. Relay SSR accordingly picks up Vand closes its front contact 3,6 to connect relay STR and battery STB in circuit with the track rails of section F-TH, whereupon relays STR and STR become energized in series with battery STB and the apparatus of section F-,H iS conditioned to reversibly operate relays STR and STR in a manner corresponding to thatl hereinbefore pointed out in connection with section lf3-1E, Front contact 38 of relay SSR is now closedand relays SK, SL and SM accordingly are supplied with energy and are caused to pickup in response to the operation of relay STR, whereupon signal SS is conditioned to display its caution aspect, and when relay SL picks up, the stick circuit of relay SSR is completed at front contact 3l of relay 5L. Additionally, relay SAP is caused to pick up when relay STR operates to its reyerse position, and relay SAP in turn picks up` relay TSR, whereupon that relay closes its `front cone tact 36 to connect relay 'ITR and battery ITlgin circuit with the rails of section 1?'--I-I. Relays TTR and 8TR thereupon become energized and are caused to operate in substantially'the saine manner that relays ITR and ZTR are cansed to operate. Front contact 38 of relay ISR is closed and with relay TITR reversibly operated, relays GK, IL and 'IM are picked up with the result that front contact 22 of relay 'ILv closes to cause relay GTPR to function as ya straight repeater relay of relay ETR, whereupon relay SNisvcaused to pick up and signal SS` accordingly is conditioned to display its clearaspect. Additionally, relay SAP picks up to condition the track circriit apparatus of the section in advance of section H-J to apply energy to the track circuits thereof, and I shall `assume that this apparatus (not shown) is effective to cause front contact122 of relay 9L to close and in turn shift the frequency at which energy impulses are supplied from bat'- tery STB to the track rails. When thisk happens, relay 'IN is picked .up and signal `IS is conditioned to display its clear aspect and does so since its energizing circuit is now complete at `front contact 42 of relay ISR. i

At the end of the slow release interval o f relay ZAPP, that relay releases to open its front contact 29 and thereby open the shunt circuit applied across the rails of section Elf-F, W-hen this happens, the first impulse of energy that .is applied to the rails of section E-F due to the interaction of relays 3K and 3M causes relay ETR to operate to its reverse position, whereupon relay 4AP picks up, and relay ,IITPR releases, thereby causing the track circuit apparatus of section E-F to be restored to its normalc'ondition in a manner to be explained in detail Ahereinaiter. In this restored condition of the apparatus of section Erf-F, the two track relays STR and 4TR are caused to be reversibly energized rst by energy supplied from battery 4'IB and then from battery STB. At this time, relay 5L is picked up, so that relay 4TPR functions as a straight repeater relay for relay 4TR and as a result relays 3K, 3L, 3M and 3N associated with relay STR are picked up. Signal 3S accordingly is conditioned to display its clear aspect andjdoes so at this time due to the fact that back 'contact I4 of relay ZAP is closed and connects Aenergy to the lamps of signal 3S.

From the foregoing description, it is readily lapparent that when a train approaches signal IS, it will receive a clear aspect if conditions in advance warrant the display of this aspect.

erned by signal IS, a shunt is momentarily appliedto the'track circuit apparatus of advance section E-F, whereupon that apparatus functions to Ycause energy to be .applied to each of the normally deenergized sections in advance of section E-F. If this happens when traic conditions Yin these advance sections are favorable, each of the advance signals is conditioned to display its clear indication, and relay SL associated with section F-H picks up to' condition the track circuitapparatus of section E-F to apply clear track circuit code to the rails of the associated section. This clear track circuit beomes elicotive after the momentarily applied shunt on relayST-R is removed, to cause signal 3S to display its clear aspect if traflc conditions permit.' I t follows, that the apparatus is so arranged that when a train approaches the normally deenergized sections, such train will cause energy to be applied to the sections prior to arriving thereto, andif tranic conditions so permit, the train will receive clear signal aspects in each of the moni tor sections.

When the train enters section E-E', both relays STR and STR are shunted and such relays assume their occupied section positions'hereinl before described wherein relay dTRis held constantly in its normal position while relay'3'I'R is held constantly in its reverse position. Relays `3L and 3N accordingly release4 to cause signal 3S to display its stop aspect, while relays 3K and 3M are caused to be intermittently energi-zed and d eenergized and relay 3M functions to intermittently connect battery STB to the track rails. These current impulses are, of course, shunted bythe train away from relay 4TR, hence relay T-Rremains constantly in its normal position while relay 3TR is held constantly in its reverse position. Y 40' As pointed out her-einbefore, when the train occupies section D-E the relays IK and IM are caused to interact in such manner as to intermittently apply impulses of energy from battery IT-B to the track rails. These relaysA IK and IM in applying such impulses of energy function as code initiating means effective after-the section becomes vacant to restore the apparatus ofthe section to its normal condition wherein thecode impulses supplied to the two track circuits-'of the section are each caused to be generated by the action ci the code impulses suppliedltoth other circuit. This restoration is eiected when the train vacates section D-E and the energy applied by battery ITB to the track rails, when relay -IM is in its normal condition, is no longer Ashunted away from relay 2TR. Under such assumed conditions, relay 2TR operates its contact IS to its right-hand position to deenergize relay 2TPR. That relay in turn releases to open the previously mentioned rst track circuit, and to close its-back contact 9 to connect battery 2 Tl3 and relay -21TR to the track rails. The second track circuit may not at this time be comrelays ITR, ZTR and IM occupy corresponding Vrelai-,ive positions and the energization of the AWhen the train enters the` sectionlDE) gov- .7.5

track relays cause their contacts to be operated 'in agreement to the'left-handposition.` Relay 3L now .deenjergized and its back contact 2'2- is closed; hence relay 2HP becomes energized and 6 at theV end of ,its slow piek-up period that relay closes its front 'contact 23 to energize relay ZTPR andlcause'that relay to close its front contact 9 to; complete the second track circuit, and when relay IM operatesk to its left-hand position, its contact 8A is in its'reverse position and thereby completes the first track circuit. YThe two track relays accordingly are caused to be reversibly ,operated `over the two track circuits and this operation of relay 2TR is detected by relays 2AP and ZAPP, Vwhich relays pick up, while the operation of relay ITR, is detected by relays IK :andl L; which relays also pick up. Relay IN does not, however, pick up at this time since the slow pick-up period `of relay 2HP is introduced into the interval that exists between successive connections of battery 2TB to the track rails, hence the frequency of such connections is relatively lowrandris insuflicient to cause relay IN to be effectively energized. VAt this time, signal IS is conditionedto display its caution indication and will do so only if back contact I4 of relay OAP is closed.

When the train enters section F-H, both relays STR and STR are shunted, and relays SL, SN and SAP release.

Back contact 40 of relay VIiAPcompletes a previously traced Vstick circuit for relay TSR, while relay SSR is now held energized over its pick-up circuit including back con- I Vtact of relay LAP. When relay SL drops it completes theA previously traced pick-up circuit ofrelaySSPR with the result that relay SSPR picks up and closes its front contact 34 to complete'its stick circuit. Relays SK and SM are now intermittently energized and relay SM operates its ,contact member 8 intermittently to its lefthand position to apply at times energy to the rails of the associated section. This energy is shunted away from relay vSTR by the train in the section.

When the train vacates section E-F, the first pulseof energy transmitted from battery 3TB overcontact 8 of relay 3M and the rails of section E-F to relay ATR causes'the track circuit apparatus of section E-F to reversibly energize relays 3TR and 4TR in substantiallyfthe same manner as was pointed out in detail for the operation of the apparatus of section DE. Relay IIAP is vcaused to pick up in response to relay 4TR Voperating intermittently to its reverse position, andwhen relay IIAP picks up, it opens the pickup circuitl of relay SSR, whereupon that relay releases and opens its front contact 32 prior to the closing of front contact 30 of relay vAAP. Re- -lay SSPRis at this time held energized over its stick circuit and this relay functions to maintain the supply of energy to the decoding relays associated with relay STR and to the rst track circuit of section F-H. At this time, however, relay STR is shunted and relay ySL accordingly is released, hence the slow pick-up period of relay III-IP is added into the intervals that exist between successive connections of battery ATB to the track rails of section E-F, and relays 3K nand 3L are energized by the operation of relay 3TR, but relay 3N is not at this time picked up. Signal. 3S accordingly is conditioned to display its caution aspect. The track circuit code that is'supplied from battery 2TB to the track rails is 'nowshifted to the clear code frequency since with relay 3L'picked up, the slow pick-up period of relay ZHP is excluded from the intervals existing `between successive connections of battery 2TB to the rails; Relay IN associated with relay ITR accordingly picks up to condition signal IS to display its clear aspect.

.When the train enters section H-J, both relays TTR and 8TR are shunted and these relays assume their respective occupied section positions. Relays 'IL and 1N release to set signal 1S at stop; relay 'ISPR is picked up over its pick-up circuit including back contact 3| of relay 1L; relays 1K and 1M are alternately energized and relay 1M operates intermittently. to impress battery 'ITB across the trackrails; and relay 8AP also releases. y y

After the Ytrain vacates section F-H, relay GTR responds to the first energy impulse that is applied to the rails of the section when relay 5M is caused to operate to its normal position, and relay STR in turn operates. to its reverse position whereupon relay BAP picks up Awhile relay BTPR releases and connects battery STB to the track rails in circuit with relays STR and STR. Relay vITR operates to its normal position, while relay STR operates to its normal position and energizes relays SK and 5M. Battery STB is then connected to the track rails to operate relays yS'I'R. and STR to their respective reverse positions, whereupon relay 6TPR releases and back contact 9 closes to establish the second track circuit which is eiective to operate relays STR and STR to their normal positions; relay SL picks up; and theI stick circuit of relay SSPR is interrupted at back contact 3| of relay SL. Relay SSPR accordingly releases to place relay STR on open circuit, and to remove energy from the decoding relays SK, SL, SM and SN associated with relay STR. The other track relay GTR remains in its normal position and its associated relay STPR becomes energized and is maintained picked up since contact 2| of relay STR is held closed in its.v normal position. Y Y The track circuit apparatus of section H-J likewise is restored to its normally deenergized condition when a train vacates the circuit. The operation of this apparatus at this time is similar to that just described for section F--H, and further detailed description of the operation is deemed unnecessary.

Y From the foregoing description, it is readily .apparent that the apparatus embodying my invention is arranged to apply energy to a track circuit only when a train approaches a circuit, and is maintained on the circuit to restore the vtrack circuit to its normal condition when a train vacates a circuit, whereupon the energy is removed from the circuit. It thus follows that the arrangement of the apparatus avoids the use of energy at all times except when the energy has the particularly useful function of establishing a control for a train approaching these sections. In this manner the supply of energy is conserved, and the wear on the contact apparatus that would normally be occasioned by constantly operating coding elements is eliminated.

In addition, itis apparent that the track circuit arrangement is such that the normally deenergized track circuits when supplied with energy, are effective to code such energy in accordance with traic conditions in advance, and also are effective to provide means whereby approach energization of the lamps of the signals isattained through the track rails andthe use of line wires customarily extended between the opposite ends of a track section, is obviated.

Although I have hereinshown and described only one formof railway traiiic controlling appa- Vratus embodying my invention, it is understood 'that various changes and modifications may be `made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a section of railway track, a rst track relay and a first track battery at one end of said section, a second track relay and a second track battery at the opposite end of said section, both-oi said track batteries and one of said track relays being normally disconnected from the rails of lsaid section, a first means effective when active for connecting said rst and second relays in circuit with the rails of said section and said first track battery, means responsive to traiic approaching said section for rendering active said rst means, means responsive to energization of said iirst and second track relays from said Arirst track battery for disconnecting said first and second relays from said iirst track battery and for connecting such relays in circuit with the track rails and said second track battery, means responsive to the energization of said first and second track relays from said second track battery for reconnecting said rst and second relays in circuit with the track rails and said rst track battery, means responsive to trailic in said section for maintaining active said rst means, and means responsive to operation of said iirstrelay for governing traic on said section.

2. In combination, a stretch of railway track including a track section, means for governing traiiic operating in a given direction in said section, energy applying means, means responsive to traiiic approaching said section in said given direction for rendering active said energy applying means, two sources of unidirectional energy one for each end of said section and each normally disconnected from the rails of said section, two polar relays one for each section end and each having a polar armature, means rendered effective by said energy applying means when active for simultaneously energizing both said relays over a circuit including the rails of said section and alternately first one and then the other of said two current sources, said two current sources being poled in such manner that current from one of the sources causes the two relays to' operate their polar armatures to one position and current from the other source causes the relays to operate their armatures to the other position, means governed by traiiic in said section for maintaining active said energy applying means, and means governed by the relay at the section end entered by a train operating in said given direction for controlling said traflic governing means.

3. In combination, a stretch of railway track including a track section, a stick relay provided with a pick-up circuit completed when a train approaches said section in a given direction and within a given zone, two sources of unidirectional current one for each end of said section, two polar relays one for each section end and each having a polar armature, means rendered effective when and only when said stick relay is picked up for simultaneously energizing both said polar relays over a circuit including the rails of said section and alternately rst one and then the other of said two current sources, said two current sources Ibeing poled in such manner that current from one of said sources causes the two polar relays to operate their polar armatures to one position and current from the other source causes the polar relays to operate their armatures CII to the other position, and a stick circuit for said stick relay governed by the one polar relay at the section entering end and completed when said one polar relay is reversibly energized.

4. In combination, a stretch of railway track including a track section, a stick relay provided with a pick-up circuit completed when a train operating on said stretch in a given direction approaches within a given zone of said section,

two sources of unidirectional current one for each end of said section, two polar relays one for each section end and each having a polar armature, circuit means for simultaneously energizing both said polar relays over a circuit including in series the windings of both of'said relays and a front contact of said stick relay and the rails of said section and alternately rst one and then the other of said sources, said two sources being poled in such manner that current from one of said sources causes the two polar relays to operate their polar armatures to one position and current from the other source causes the polar'relays to operate their polar armatures to another position, and means governed by at least one of said polar relays for establishing a stick circuit for said stick relay when said polar relays are caused to be reversibly operated.

5. In combination, a stretch of railway track including two track sections, a track circuit for one of said sections comprising two current sources one for each end of the section and two polar relays one for each section end and means for simultaneously energizing both said polar relays over a circuit including in series the windings of said polar relays and the rails of said section and alternately riirst one and then the other of said sources, said sources being oriented in such manner that current from one source causes operation of said polar relays in one direction and current from the other source causes operation of said polar relays in the other direction, means controlled by one of said polar relays for governing trailic in said one section, approach control means governed by the other of said polar relays, track circuit apparatus for the other of said sections comprising two current sources one for each end of said other section and two polar relays one for each of said other section ends, circuit means controlled by said approach control means to be effective when said one section is occupied by a train for simultaneously energizing both of the polar relays of said other section over a circuit which includes in series the Windings of both of said' polar relays of said other section and the rails of said other section and alternately rst one and then the other of the said two sources of said other section, said sources of said other section being oriented in such manner that current from one of such sources causes both of the associated polar relays to operate in one direction and current from the other of such sources causes both of the associated polar relays to operate in another direction, and means governed by one of said polar relays of said other section for governing traiiic vin said other section.

6. In combination, a stretch of railway track including two track sections, two current sources one for each end of one` of said sections and two polar relays one for each end of said one section, means for simultaneously energizing both said relays over a track circuit including in series the windings of said polar relays and the rails of said one section and alternately first one and then the other of said current sources, said sources being oriented to reversibly operate said two polar relays, means controlled by one of said polar relays for governing traffic in said one section, approach control means governed by the other of said polar relays, two other current sources one for each end of the other of said two sections and two other polar relays one for each end of said other section, means controlled by said approach control means to be effective when a shunt path is established across the track circuit of said one section for simultaneously energizing both of said other polar relays over a track circuit including inseries the windings of said other polar relays and the rails of said other section and alternately iirst one and then the other of said other two sources, said other sources being oriented to reversibly operate said other polar relays, and means governed kb y one of said other polar relays for modifying the control established by said one polar relay over said traflic governing means.

7. In combination, a stretch of railway track including two track sections, two current sources one for each end of one of said sections and two polar relays one for each end of said one section, means for simultaneously energizing both said relays over a track circuit including in series the windings of said polar relays and the rails of said one section and alternately first one and then the other of said current sources, said sources being oriented to reversibly operate said two polar relays, means controlled by one of said polar relays for governing traiiic in said one section, approach control means governed by the other of said polar relays, two other current sources one for each end of the'other of said two sections and two other polar relays one for each end of said other section,l

means controlled by said approach control means to be effective when a shunt path is established across the track circuit of said one section for simultaneously energizing both of said other polar relays over a track circuit including in series they windings of said other polar relays and the rails of said other section and alternately first one and then" the other of said other two sources, said other sources being oriented to reversibly operate said oth-er polar relays, means controlled by one of said other polar relays for governing traiic in said other section, and other means governed by said one other polar relay for modifying the control established by said one polar relay over its said 'associated traic governing means.

8. In combination, a stretch of railway track including two track sections, two current sources one for each end of one of said sections and two polar relays one for each end of said one section, means for simultaneously energizing both said relays over a track circuit including in series the windings of said polar relays and the rails of said one section and alternately rst one and then the other of said current sources, said sources Ibeing oriented to reversibly operate said two polar relays, means controlled by one of said polar relays for governing trailic in said one section in accordance with the rate of reversible operation of said one polar relay, approach control means governed by the other of said polar relays, two other current sources one for each end of the other of said two sections and two other polar relays one for each end of said other section, means controlled by said approach control means to be effective when a shunt path Vis established across the track circuit of said one section for simultaneously energizing both of said other polar relays over a track circuit including in series the windings of said other polar relays and the rails of said other section and alternately first one and then the other of said other 4two sources, said other sources being oriented to reversibly operate said other polar relays, and means governed by one of said other polar relays for controlling the rate at which the polar relays of said one section are reversibly operated.

9. In combination, a stretch of railway track including two track sections, two current sources one for each end of one of said sections and two polar relays one for each end of said one section, means for simultaneously energizing both said relays over a track circuit including in series the windings of `said` polar relays and the rails of said one section andalternately first one and then the other of said current sources, said sources being oriented to reversibly operate said two polar relays, means controlled by one of said polar relays for governing traic in said one section in accordance with the rate of reversible operation of said one polar relay, approach control means governed by the other of said polar relays, two other current sources one for each` end of the other of said two sections and two other polar relays one for each end. of said other section, means controlled by said approach control means to be eiective when a shunt path is established across the track circuitl of said one section for simultaneously energizing both of said other polar relays over a track circuit including in series'the windings of said other polar relays and the rails of said other section and alternately rst one and then the other of said other two sources, said other sources being oriented to reversibly operate said other polar relays, means controlled by one of said other polar relays for governing traic in said other section and rendered effective by said approach control means, and means governed by said one other polar relay for controlling the rate of reversible operation of the polar relays of said one section.

10. In combination, a stretch of railway track including a plurality of successive adjoining track sections, means for providing normally energized closed circuit track circuits for the two sections of said stretch rst to be traversed by a train operating in a given direction over said stretch, means rendered effective Ywhen the first encountered one of said two sections is occupied by a train for applying a shunt momentarily across the rails of the second of said two track sections, means rendered effective when Said momentary shuntis applied to said second section for providing each of the remaining sections of track with a closed circuit track circuit, and means rendered effective by the track circuit of each of said other sections for maintaining such track circuit after said momentary shunt is removed and until the section is traversed by the train.

JOHN M. PELIKAN. 

